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Family: Poaceae
Fétuque Rouge des Sables, more...Red Fescue
[Festuca rubra subsp. arenaria (Osbeck) F. Aresch., moreFestuca rubra subsp. clarkei (Stapf) St.-Yves] |
Stephen J. Darbyshire and Leon E. Pavlick† Plants usually rhizomatous, usually loosely to densely ces-pitose, culms sometimes single and widely spaced, sometimes stoloniferous. Culms (8)10–120 (130) cm, erect or decumbent, glabrous and smooth. Sheaths closed for about 3/4 their length when young, readily splitting with age, usually pubescent, at least distally, hairs retrorse or antrorse, sometimes glabrous, not persistent, older vegetative shoot sheaths shredding into fibers; collarsglabrous; ligules 0.1–0.5 mm; blades usually conduplicate or convolute and 0.3–2.5 mm in diameter, sometimes flat and 1.5–7 mm wide, abaxial surfaces glabrous, smooth or scabrous, adaxial surfaces scabrous or pubescent, veins 5–9(13), ribs (3)5–7(9), usually conspicuous; abaxial sclerenchyma in 5–9(13) discrete or partly confluent strands, rarely forming a complete band; adaxial sclerenchyma sometimes present in fascicles opposite the veins; girders and pillars not developed. Inflorescences (2)3.5–25(30) cm, usually open or loosely contracted panicles, occasionally racemes, with 1–3 branches per node, lower branches with 2+ spikelets; branches erect or spreading, stiff or lax, glabrous, scabrous, or pubescent. Spikelets (6)7–17 mm, with 3–10 florets. Glumes ovate-lanceolate to lanceolate, exceeded by the distal florets; lower glumes (1.5)2–6(7) mm; upper glumes (3)3.5–8.5 mm; lemmas 4–9.5 mm, usually glabrous and smooth, sometimes scabrous towards the apices, sometimes densely pubescent throughout, attenuate or acuminate in side view, awned, awns (0.1)0.4–4.5 mm; paleas slightly shorter than to about equaling the lemmas, intercostal region puberulent distally; anthers 1.8–4.5 mm; ovary apices glabrous. 2n = 28, 42, 56, 70. Festuca rubra is interpreted here as a morphologically diverse polyploid complex that is widely distributed in the arctic and temperate zones of Europe, Asia, and North America. Its treatment is complicated by the fact that Eurasian material has been introduced in other parts of the world. In addition, hundreds of forage and turf cultivars have been developed, many of which have also been widely distributed. Within the complex, morphologically, ecologically, geographically, and/or cytogenetically distinct taxa have been described, named, and given various taxonomic ranks. In some cases these taxa represent extremes, and in other cases they are morphologically intermediate between other taxa. Moreover, hybridization and/or introgression between native taxa, and between native and non-native taxa, may be occurring. In Iceland and southern Greenland, putative hybrids between Festuca frederikseniae and F. rubra have been reported, and named F. villosa-vivipara (Rosenv.) E.B. Alexeev. Overlap in morphological characters between most taxa in the complex has led some taxonomists to ignore the variation within the complex, calling all its members Festuca rubra without qualification. This obscures what is known about the complex, and presents an extremely heterogeneous assemblage of plants as a single “species”—or a mega-species. The following account attempts to reflect the genetic diversity of the F. rubra complex in the Flora region. All the taxa are recognized as subspecies, but they are not necessarily equivalent in terms of their distinction and genetic isolation. Much more work on the taxonomy of the F. rubra complex is needed before the boundaries of individual taxa can be firmly established. Some variants that need attention are (1) plants growing on the sandy shores of the Great Lakes that have glaucous leaves and spikelets, sometimes treated as F. rubravar. juncea (Hack.) K. Richt., (2) native plants along the James Bay and Hudson Bay shore that are ecologically distinct from F. rubra subsp. rubra, (3) native plants growing in marshes, sometimes called F. rubra var. megastachys (Gaudin) Hegi (Dore and McNeill 1980), (4) seashore variants along the Atlantic coast of North America, (5) plants with glaucescent leaves and spikelets which are widely distributed in the Flora region and have been called F. rubra subsp. glaucodea Piper, (6) the widespread variant with pubescent to villous lemmas, sometimes called F. rubra f. squarrosa (Hartm.) Holmb. Stephen J. Darbyshire and Leon E. Pavlick† Plants strongly rhizomatous, usually loosely cespitose, with several culms arising from the same tuft. Culms (10)30–60 cm. Sheaths pubescent, shredding into fibers, cauline leaf sheaths tightly enclosing the culms; vegetative shoot blades 0.8–1(1.5) mm in diameter, conduplicate, veins (5)7–9(13), ribs (3)5–7(9), abaxial surfaces smooth or scabrous, green or glaucous, adaxial surfaces scabrous or pubescent; cauline blades (1)5–15(20) cm, conduplicate or flat; abaxial sclerenchyma in 5–7(9) broad strands, often confluent, sometimes forming a continuous band; adaxial sclerenchymastrands usually present. Inflorescences (5.5)7–15(16) cm, open, lanceolate, usually completely exserted from the uppermost leaf sheaths; branchesscabrous. Spikelets (7)9–10(13) mm, with (4)6–8(9) florets. Glumes ovate-lanceolate, acute; lower glumes 3–6(6.5) mm; upper glumes (3.5)4–6.5(8.5) mm; lemmas 6–8(9.5) mm, lanceolate, green, sometimes glaucous, glabrous or villous, apices acute to acuminate, awned, awns (0.5)1–2(3) mm; anthers 2.6–4.5 mm. 2n = 56. Festuca rubra subsp. arenaria is a European taxon that grows in maritime sands and gravels. It is known in the Flora region only from one specimen collected on Vancouver Island; it is not known to have persisted. The description is based on the range of variation seen in Europe. In the Flora region, the name has long been misapplied to F. richardsonii Hook. [= F. rubra subsp. arctica], which also has hairy lemmas. |
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